I am creating a Saas Solution. The solution has been built on a Kubernates Cluster hosted on GKE. The question is, if I am creating a web app where people can sign up, wis there no problem creating a kubernates cluster per customer that signs up.
How to do multi-tenancy on Kubernetes is not a trivial problem, and there is no single solution that fits all use cases.
See the GKE Multi-tenancy Overview documentation to learn how you can share a cluster among multiple users and when does it make sense to create separate clusters per user/team.
I also have a talk from Google Cloud Next'18 that explains multi-tenancy modes for PaaS/SaaS, enterprise and Kubernetes-as-a-Service use cases here: https://www.youtube.com/watch?v=RkY8u1_f5yY which is adopted from David Oppenheimer’s deep dive talk from KubeCon: https://www.youtube.com/watch?v=xygE8DbwJ7c
In SaaS world where you control everything, you should determine whether your users can run arbitrary code or make malicious requests through the service you provide to them. If the answer is no, one BIG cluster may suffice, otherwise, you should consider separating these tenants, possibly into different namespaces in a single cluster, or to entirely separate clusters.
P.S. Please try to use better grammar and be more descriptive while asking questions on Stack Overflow. Right now it's totally not clear what you’re asking.